Cryopreservation Techniques for Ram Sperm

Abstract

Germplasm storage and transportation in artificial insemination (AI) and other advanced technologies are facilitated by cryopreservation. In reproduction, the cryopreservation of sperm allows it to be transported across vast distances and used even after the sire’s death. However, the technique of cryopreservation might damage sperm and limit their activity. Several cryobiological investigations have reported that the integrity of the sperm membrane is frequently involved in the physical and biological elements that affect sperm survival at low temperatures during the cryopreservation process. However, successful cryopreservation of ram sperm is still a work in progress because a considerable percentage of sperm do not survive the freezing and thawing process. Sperms are destroyed during cryopreservation of semen due to varying concentrations of cryoprotective chemicals and if semen is not cooled at optimal cooling rates. Hence, it is crucial to know the optimum cooling rates with freezing and thawing protocols for maximum recovery of viable and functional sperm cells for a successful cryo-freezing of ram spermatozoa. Therefore, the current study compiled and compared the research on the impact of different cryopreservation procedures, cooling rates, equilibration time, and thawing protocols on post-thaw ram semen quality.

Ram Semen Cryopreservation for Portuguese Native Breeds: Season and Breed Effects on Semen Quality Variation

“…Vozaf et al [27] reported an IM decrease of 15.1-18.4% in their study, but a variation of 15 to 28% was observed in the Merino ram (Spain) according to three freezing methodologies [30], and up to 49.1% in Manchega rams (Spain) [31]. In a recent review considering more than 20 ram breeds, the IM decrease in thawed SPZ varied between 22.7% and 74.6% [32]. Probably, breed differences in seminal traits of frozen semen may be explained by inherent susceptibilities of SPZ cells to the deleterious effects of cryopreservation and evaluation methods used in the different studies [33].…”

Exploring Endogenous and Exogenous Factors for Successful Artificial Insemination in Sheep: A Global Overview

“…Additionally, preserved semen has become an important tool for genetic improvement and has streamlined semen transport. Therefore, the dilution and cooling of semen play crucial roles in inseminating multiple females and providing essential nutrients and protection against pH changes [ 85 ]. Extensive studies have investigated this topic using several extenders.…”

Inclusion of Spirulina platensis and Salvia verbenaca extracts to boost semen quality and fertilization ability in sheep

“…Besides, it increases insemination's speed in the field (Yang et al, 2018). However, during liquid storage, the accumulation of reactive oxygen species (ROS) and the oxidation of sperm plasma membrane cause changes in the spermatozoa and decrease the sperm quality and fertility (Allai et al, 2018; Saha et al, 2022). To avoid such negative effects, the inclusion of antioxidants in extenders can minimize the negative effect of ROS and maintain sperm quality after liquid storage (Alenezy et al, 2019).…”